1969-03-26 — Page 23

IXERENDE LIEK

26 MAR 1949

番九每月二年巴

CC英文中學會考試題預習

化墨科 (二十)

WAH KU YAT PO 報日僑茶

CITY HALL

You are provided with the following compound

the

usual chemical apparatus water, a source of heat and nothing else,

I

concentrated sulphuric acid

II ethyl alcohol

III potassium nitraza

IV sodium hydroxide

ammonium chloride

三期星 日六廿月三年九六九一层叠年八十五圈罠樂中

(接第六張第二六)

中

英文科 (廿一 )

士俊

sodium chloride la composta ar 1ons rather than

acnles. The best experimental evidence in support

of this statement is that

both sodium and chloring lona have the eléctronis structure of inert gases a

Bsodium chloride is very soluble in water Cfused sodium chloride is a good conductor or

electricity!

Dan aqueous solution of sodium chloride is a

good conductor of electricity

in the electrolysis of an aqueous solution of sodium chloride, sodium ions migrate towards the cathode, while chloride ions migrate towards the anoda

AN GIGNANT, whose symbol is represented by written sa, This means that the mumber of.

which or the following compounas couin you prepare.

Long

longest

(6) Can you

ethylene

lengthen

ammonia

length

nitrous

methane

E nitric acid.

SOLUTIONS

C The fact that the compound itself is a good

conductor of electricity is the best experimental avidence in support of this statement.

Na C1 Na • CI**

in ract in the electrolysis of fused sodium chloride, metallic sodium is obtained at the cathode and chlorine is obtained at the anode.

The symbol

means the atomic number of is 13 x, that is, there are x protons in the nucleus and x electrons surrounding the nucleus, y is the atomis mass of the element. (y-x) is therefore the mumber of Boutrons in the nucleus.

The action

H2O

steam on red hot coke is endothermis

this skirt for me?,

deadly

death

(f) The thief hid his

weapon under his arm.

dead

died

In each line underline the word which has the same or nearly the same sound as the first one.

Example: SAIL

ride

DONE gone Cruel dall BAD bed NOSE lose TURN

bone

"none

rulès:

fool

Bad

laid

does

goes

torn

HAIR

star

SALE

stile

tail

dial

BREAK

wake

Weak

leak

SET

Bat

seat

late

3) RUN

Bome

bead

electrons in the nucleus is protons in the nucleus is x

protons in the nucleus is

neutrons in the nucleus is y

electrons surrounding the nucleus

Some of the following reactions are exothermic,

The action of air on red hot coke

EI The action of steam on red hot coke

III The combination of nitrogen and hydrogen to

XOTM, AMMONI 20

TV The oxidation or ammonia to form nitric oxide

The action of water on quicklimm

Which of the following alternatives is correct?

I and II only

IV and only

I II and III only

III, IV and V only

all except II

siements, sodium and potassium, are never round

in the free stata in nature, because they are

I

the lightest metallic elements

II too heavy

III strongly electronegative

IV powerful reducing agents

V ́ very reactive elementa

Which of the following alternativen is correc

AI and III only

BIY and V only

C I, III and V only

DII, III and V only

B All but. II

30 ml, or a solution or sulphuric acid can neutraliss

15 ml. of a solution of N/5 caustic soda. The concentration of the acid in grams par litreis

· 19.6 9.9

Calculate the weight of litharge obtained from 33.1 grams of lead nitrate

A 11.15 gms.

CO

H

neat

Thus, in the preparation or water gas, the action between steam and carbon ceases because the temperature of the coke falls. It is then necessary to pass a current of air over the coke to make the coke bot enough to allow it to react with steam again.

Potassium and spalum are such powerful reducing agents and are so very reactive that they form - compounds very easily.

30 ml or

15 ml. Of.

Normality of

soluti

32+64

MOL, WUT or

Baulv, wt. of H2SO

Hence concentration of H2SO, solution

2Pb(NO

2(207-28-96)

2x331

2(207+16) 2x223

પ્રાદ

w of Litharge that can be obtained from 331

of lead nitrate = 223 25.

Wt. of Litharge that can be obtained from 33-2 gm of lead nitrate 22.3 8

Chlorine will oxidise ammonia to nitrogen. other product of reaction being ammonium chloride.

Take the not out of the following sentences." WE

out each sentence in the space and make other changes chich are necessary,

Example's

It will not be very cold to-morrow. It will be cold to-morrow

The servant does not smoke.

We have not eaten our food yet,

He does not live here

have never been to England before

Why won't they leave now?.

5. Read the following passage carefully

The sun stopped shining and suddenly we felt big drops of water falling on us. Looking up we saw that a huge black cloud had covered" the sun and the patter of large rain drops had turned to a heavy

We started running up the beach tovarus shelter, and then we stopped and stared at one another and burst out laughing, AS TE FOTe in our swim suits and as it was a hot day so that even the

for heavy rain felt war, we did not need to shelter. Even our clothes were safely dry. and mine were in the nut and John's and Ton'a were in the cave. Te danced on the sande with the rala”. pouring over us,"

Each of the following sentences is about the passag Put a tick() against the group of words which gives the best meaning.

B 22.3 8.

C 33,1 go.

D 44.6 gms,

322.4 litres

7. When chlorine reacte with ammonia, the Following

products may be formed:

I

amncrxium chloride

II hydrogen chloride

III nitric asid -

IV nitrogen

V

nitrogen trichloride

Which of the following alternatives as correct?

I only

BLY only

II and V only

DL, II, III only

IV. V only

the electrolysis of a dilute solution of sulphuric Bold

the amount or acid is unchanged at the end of the experiment

II the acid becomes more concentrated near the anode III the solution becomes alkaline near the cathode

IV hydrogen is liberated at the cathode

V

oxygen is liberated at the anode

Which of the following alternativas ás correct?-

I only

TV and V only.

I, II and III only

I, IV and V only

All five

Which of following sodium compounds in solution will

turn red litma blue2

sodium acetate

II sodium carbonate

III sodium chloride

TV Bodium nitrate

sodium sulphate

Which of the alternatives is correct?

I and II only

IV and V only

I, II and III only

All, IV and V only All five compounds

3012 BNH3 6 NE

chlorine 13 present in excess, trichloride may also be formed

HO

2N01

itroge

Luring the electrolysis of dilute sulphuric sold, Ehe hydrogen ions migrate to the cathode making the acid near the cathode more concentrated. At the same time, the hydrogen ions are discharged and hydrogen is evolved.

The hydroxyi ions migrate to anoce, making the solution near the anode alkaline. When the hydroxyl ions are discharged, mygen is evolved

462120

No acid is used up during electrolysis, ano, án,

a result, the amount of acid is unchanged at the and of the experiment.

BOGA SONIUM carbonate and sodium acetate ara the salts of strong bases and weak acids. When they dissolve in water

of acid ére

Leaving

ions in solution The result alkalin to Litmus

H200

weag nei

Docurs moleculsa

sxossa of hydroxyl

ution is tharaf ora

(a) The sun stopped shining beosUSE

luit was dark

2. 11 was covered by the cloud.

3, it was raining.

it was in the sky,

(b) We ran for shelter becaus

11t was raining.

2. it was very hot.

there was a huge black cloud in the we were hungry.

cold day.

rainy day

warm day

not

AS WE Here in our own suite we did not need.

1 to jump into the major, 2. to run for shelter.

3. to play on the sanda.

d. to look at one another.

Sven our clothes were

1. safely dry-

2. near the rock.

3. on the floor.

in the tent..

rethane is prepared in the laboratory by th setim of sodium acetate on soda-lims.

CH↑ Ma2 CO2

120 scorio acıa mesa provided na MULE, sodium acetate could have been meusred and also methana:

'Anawera to Test 20

of, (b) for (e) off, (a) by. (0) or, (f) ot about:

I am not speaking English fluently.

He does like to help the poor.

The girl is not singing a song.

(d) The thief did not steal my watch yesterday:

Mary has not saten her breakfast,

k', (b) oh, (c) k, (d) oh,

(a) sixteen years old. (b) cautiously, (0) pale

and frightened, (d) he began to swim properly,

8

Tim could svin as well as his brother.

who, (b) choss, (c) which, (d) on whick, (•)